JP2001169502A - Bearing device of motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively reject foreign matters such as dusts or the like into a bearing case from a through-hole of a bracket. SOLUTION: An external side of a bracket 6 where a rotor shaft 4a is projected is provided with a sealing member 16 consisting of a member having excellent elasticity such as rubber or the like, while the end point side where the rotor shaft 4a of the sealing member 16 is projected is provided with a closing member 18 for closing an insertion hole b3 within the range not to prevent rotation of the rotor shaft 4a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a bearing device for an electric motor, and more particularly, to a bearing device capable of preventing entry of moisture and the like containing dust and salt.

[0002]

2. Description of the Related Art Conventionally, various electric motors have been used as a drive source for a blower or the like used for many home electric appliances such as heating / cooling equipment. Most of the electric motors use ball bearings in their bearings.
That is, a rotor rotatably mounted on a stator core of an electric motor includes a ball bearing mounted on both ends of a rotor shaft, a housing in which the stator core is fitted, and a cover for closing an open end of the housing. By being inserted into the bearing housings formed respectively, the rotor is rotatably supported and held on the stator core. The rotor is rotated in a predetermined direction via the ball bearing by energizing a coil wound around the stator core.

[0003]

However, in a configuration in which the rotor is rotatably supported by using a ball bearing, the bearing housing on the housing side is normally closed because the rotor shaft does not protrude to the outside. Because of this, it is possible to prevent dust and foreign substances that adversely affect the ball bearings from entering the bearing housing, but on the cover side of the bearing housing, a rotor of a rotor on which a fan of a blower is mounted. A through-hole for projecting the shaft to the outside is provided, and the rotor shaft projects through the through-hole to the outside with a small gap. For this reason, when an electric motor is used as a drive source of a blower that supplies air to a combustion section (burner section) of a heating device to improve combustion efficiency, for example, a ball bearing that rotatably supports a rotor is used. Since it is sealed only by the shield plate, it has been difficult to properly prevent the intrusion of dust or foreign matter that flows when air is introduced into the blower.

That is, since the ball bearing itself generally has only a shield plate for protecting the ball inserted between the inner and outer races from dust and the like, the air is introduced when the blower is operated. At the same time, dust including salt, moisture containing salt, etc. can easily enter the bearing housing from the gap of the through hole of the cover from which the rotor shaft projects,
It accumulates in the bearing housing over time, or enters the ball bearing through a narrow gap between the shield plate of the ball bearing and the inner and outer races. As a result, the outer race surface of the ball bearing and the outer race is roughened, or the ball and the inside of the bearing housing are rusted, thereby lowering the rotation function of the ball bearing and generating a noise generating factor.
There is a problem that the life of the ball bearing is shortened, the operation of the motor becomes difficult, and the reliability of equipment using the motor is impaired.

SUMMARY OF THE INVENTION In order to solve the above-mentioned various problems, the present invention satisfactorily improves the ability of outside air containing dust, salt and the like to enter a bearing housing, and reliably improves the function of a ball bearing. It is an object of the present invention to provide a bearing device for an electric motor, which makes it possible.

[0006]

In order to solve the above-mentioned various problems, a bearing device for an electric motor according to the present invention comprises a rotor mounted on a rotor shaft and a stator core opposed to the rotor. And a pair of brackets having a bearing housing formed at the center position, and ball bearings attached to both ends of the rotor shaft.The rotor is rotatably inserted into the stator core and inserted from both sides thereof. A pair of brackets rotatably supporting the rotor with the ball bearings at both ends of the rotor shaft fitted into the bearing housing, and a stator core with the rotor shaft protruding from the through hole of one bracket. In the electric motor, the sealing member made of a member having excellent elasticity such as rubber is covered on the outside of the bracket from which the rotor shaft is projected in a state where the rotor shaft is inserted through the insertion hole. Wear The distal end side of the rotor shaft of Kifutome member protrudes, characterized in that the provided the closure for closing the insertion hole in a range that does not interfere with the rotation of the rotor shaft.

Further, in the bearing device for an electric motor according to claim 1, a concave portion for accommodating a thin plate-shaped closing member is formed in the distal end portion of the sealing member, and the thin plate-shaped closing member is provided in the concave portion. The insertion hole can be closed from the outside by accommodating the rotor shaft in a state of being loosely fitted to a rotor shaft protruding from a distal end portion of the sealing member.

[0008] Further, in the bearing device for an electric motor according to claim 1, a concave portion for fitting a closed-end having a bottomed cylindrical shape is formed at a tip end portion of the sealing member, and the closed-end cylindrical shape is formed. The plug is loosely fitted to a rotor shaft protruding from the distal end portion of the sealing member with its opening side facing the insertion hole, and is fitted into the recessed portion, whereby the insertion hole is formed. It can be closed from the outside.

Further, in the bearing device for an electric motor according to the present invention, a fitting groove is provided around the leading end of the insertion hole of the sealing member, and the fitting groove has a smaller diameter than the insertion hole.
And, by fitting a ring-shaped closing body having a through-hole slightly larger in diameter than the rotor shaft, it is possible to close the insertion hole in a state where the rotor shaft is inserted through the through-hole. Features.

Further, in the bearing device for an electric motor according to claim 1, a thin film-shaped closing member having a through hole smaller in diameter than a rotor shaft is provided in an opening of an insertion hole opened at a tip end of the sealing member. It is formed integrally with the sealing member, the rotor shaft is inserted into the through hole, and the closing body is slid in contact with the outer peripheral surface of the rotor shaft in a deformed state using elasticity, so that the insertion hole is formed. Can be closed.

Further, in the bearing device for an electric motor according to any one of claims 2 to 5, the sealing member has a groove formed in an insertion hole through which a rotor shaft is inserted and an inner surface corresponding to an outer surface of the bearing housing. The groove is filled with a semi-solid viscous lubricant, and an oil film of the lubricant is provided between the rotor shaft and the groove.

Further, in the bearing device for an electric motor according to claim 6, a thin plate-shaped collar having a small coefficient of friction is loosely fitted to the rotor shaft between the sealing member and the bearing housing. The oil film of the lubricant is formed between the sealing member and the collar with a semi-solid viscous lubricant filled in the concave groove at a position corresponding to the collar.

According to the present invention, a sealing member made of a material having excellent elasticity, such as rubber or synthetic resin, is attached to the outside of a bracket from which the rotor shaft protrudes, with the rotor shaft being inserted through the insertion hole. A closing body that closes the insertion hole is provided on the tip side of the sealing member from which the rotor shaft projects so long as the rotation of the rotor shaft is not hindered. It is possible to satisfactorily prevent the dust and the like contained in the ball bearing from entering through the through-hole of the bracket on the side where the rotor shaft protrudes, thereby shortening the life of the ball bearing due to the entry of the dust and the like. The problem can be surely solved, and the electric motor can be driven in a stable state for a long time, which is convenient.

[0014]

FIG. 1 is a block diagram showing an embodiment of the present invention.
An example in which the present invention is applied to an electric motor used for a blower will be described with reference to FIG. FIG. 1 is a cutaway sectional view of a main part of a blower generally used conventionally, and the blower A is shown in FIG.
As shown by, for example, a shaded coil type electric motor 1
And a blower 7 for blowing air to a burner portion of a hot water supply device (not shown) by rotating the electric motor 1 or discharging combustion gas.

As shown in FIG. 1, the electric motor 1 is rotatably inserted into a stator core 3 having a coil bobbin 2 wound with a coil (not shown) mounted on one side and an insertion hole provided on the other side of the stator core 3. And a bracket 6, 6 a provided with ball bearings 5, 5 a for rotatably supporting a rotor shaft 4 a pivotally mounted on the rotor 4 and mounted on the stator core 3. I have.

As shown in FIG. 1, the blower means 7 includes two turbofans 8 and 9 arranged on a rotor shaft 4a of the electric motor 1 and two turbofans 8 and 9 for individually accommodating the turbofans 8 and 9 respectively. A first and a second fan covers 10 and 11;
And a bottom plate 12 for closing the opening of the fan cover 10. Note that, in FIG.
Is a discharge port provided in the bottom plate 12.

When assembling the blower means 7, first, a mounting hole 12a opened at the center of the bottom plate 12 is provided.
The first turbofan 8 is fixed to the rotor shaft 4a of the electric motor 1 projecting from the first plate, and then the first fan cover 10 opened around the through hole 13 in the bottom plate 12 is fixed to the bottom plate 12 by screwing or the like. Attach. Then, the first fan cover 1
The second end of the rotor shaft 4a projecting from the
Then, a second fan cover 11 opened around the suction port 14 is attached on the first fan cover 10 by using screws or the like, so that the blowing means 7 Is completed.

Next, reference numeral 16 shown in FIG. 1 denotes a cap-shaped sealing member attached to the outer surface of the bracket 6 on the side from which the rotor shaft 4a protrudes, and the structure thereof will be described with reference to FIGS. . 2 and 3, the sealing member 16 is a bracket 6
A large-diameter large ring portion b1 covering the outer surface of the bearing housing a accommodating the ball bearing 5, and a through-hole for inserting the rotor shaft 4a protruding from a through-hole a1 formed in the back wall of the bearing housing a. It has a small-diameter small ring portion b2 integrally formed with the annular portion b1 and having a small diameter b2. The sealing member 16 is formed by molding a material having excellent elasticity such as rubber or synthetic resin (for example, polytetrafluoroethylene).

A first concave groove b4 is formed in a concave portion b6 on the inner surface corresponding to the back wall of the bracket 6 of the large ring portion b1 of the sealing member 16 at a position near the insertion hole b3. A second concave groove b5 is formed in the insertion hole b3 of the small ring portion b2 so as to correspond to the outer peripheral surface of the rotor shaft 4a, and a small ring groove corresponding to the bottom plate 12 of the blowing means 7 is provided. A recess b7 for accommodating a thin plate-like closing member 18 that closes the insertion hole b3 within a range not to hinder the rotation of the rotor shaft 4a at a predetermined depth dimension in the axial direction is provided at the tip of the portion b2. It is recessed.

Subsequently, when the sealing member 16 is attached to the bracket 6, the semi-solid viscous lubricant (for example, a lubricating agent) is inserted into the concave grooves b4 and b5 of the large and small ring portions b1 and b2. Grease) O1 and O2 are filled, and a collar 17 made of a synthetic resin excellent in oil resistance, heat resistance and wear resistance is loosely fitted to the rotor shaft 4a, and the rotor is inserted into the insertion hole b3 of the small ring portion b2. By inserting the shaft 4a and fitting the large ring b1 into the bearing housing a of the bracket 6 by utilizing the elasticity of the large ring b1 as shown in FIG. Mount on the back.

Thereafter, a thin plate-like closing member 18 made of a synthetic resin having excellent oil resistance, heat resistance and abrasion resistance similar to the collar 17 is attached to the rotor shaft 4a projecting from the insertion hole b3 of the small ring portion b2. With the closing body 18 housed in the recess b7 formed by recessing the tip of the small ring portion b2, the tip of the small ring portion b2 is inserted into the bottom plate of the blowing means 7 as shown in FIG. 1
2, the bottom plate 12 and the electric motor 1 are integrally connected and fixed to each other using mounting bolts and nuts (not shown), thereby forming the blower A as shown in FIG. I do.

Next, the operation will be described. When current is supplied to a coil (not shown) wound around the coil bobbin 2 of the electric motor 1 to rotate the rotor 4, the first
The second turbo fans 8 and 9 rotate, and supply the outside air to the blowing means 7.
The air is sucked from a suction port 14 provided in the second fan cover 11, and the sucked outside air is pressure-fed in the blowing means 7, while passing from a discharge port 15 provided in the bottom plate 12 through a flow hole 13 through a feeding pipe (not shown). For example, the pressure is fed to a burner of a hot water supply device (not shown). When the outside air is pressure-fed in the blowing means 7, the bottom plate 12 of the blowing means 7 has the mounting hole 12 a
Sealing member 16 attached to the outer periphery of the bearing housing a of the bracket 6 of FIG.
Is sealed airtight so that no gap is formed, so that the outside air does not leak to the outside at all, and the outside air can be satisfactorily pumped and fed to the burner portion of the water heater.

When the outside air is fed or fed, if foreign matter such as snow or dust flows into the outside air or if the outside air itself contains salt (the blower A is generally installed outdoors). ), These foreign substances and salts etc.
4 flows into the blowing means 7 and is supplied from the discharge port 15 to the burner together with the outside air. However, there is no particular problem if all the foreign matter and the like flowing into the blowing means 7 is discharged from the discharge port 15. However, the outside air is pressure-fed by the first and second turbo fans 8 and 9, and during the pressure feeding, The outside air of the portion tends to flow out of the mounting hole 12a of the bottom plate 12 to the outside.

Since the mounting hole 12a is closed by the sealing member 16 attached to the outer surface of the bracket 6, the outside air passes through the insertion hole b3 of the sealing member 16 and enters the bearing housing a of the bracket 6. Attempts to penetrate, but the mounting hole 12
Since the closing member 18 is housed in the recess b7 at the tip end of the sealing member 16 corresponding to the opening a, the foreign matter such as dust contained in the outside air is stored in the closing member b7. 18 prevents the bracket 6 from entering the bearing housing a. On the other hand, since a minute gap is provided between the closing member 18 and the rotor shaft 4a so as not to hinder the rotation of the rotor shaft 4a, moisture (humidity), salt, etc. contained in the outside air are provided. Tends to enter the bearing housing a of the bracket 6 from the minute gap or the minute gap between the closing body 18 and the bottom plate 12 and between the closing body 18 and the bottom of the recess b7.

At this time, the rotor shaft 4a is connected to the electric motor 1
Is heated to the extent that the operation of the electric motor 1 is not hindered by the heat generated by the rotation of the rotor 4 (the rotation of the rotor 4), and this heat causes the lubricants O1, O2 is softened to form an oil film in a small gap between the outer circumference of the rotor shaft 4a corresponding to the concave groove b5 and the collar 17 corresponding to the concave groove b4. The through hole a1 of the perforated rotor shaft 4a is sealed from the outside by the oil film of the lubricants O1 and O2.

Accordingly, moisture, salt, and the like that enter the sealing member 16 from a minute gap between the rotor shaft 4a and the closing member 18 are blocked by the oil films of the lubricants O1 and O2.
From entering from the through-holes a ₁ of the bracket 6 to the bearing housing in a can be reliably prevented. As a result, it is possible to maintain good environmental resistance to the bearing housing a and the ball bearing 5, and
The operation of the electric motor 1 can be maintained smoothly for a long time, and the reliability of the electric motor 1 can be significantly improved.

When the blower A is used with its suction port 14 facing downward, the heated rotor shaft 4
The lubricants O1 and O2 softened by the heat of a try to leak out from the insertion hole b3 of the sealing member 16 to the outside. Since the closing body 18 is housed in a state where the insertion hole b3 is closed, the lubricant O
1, O2 can be prevented from leaking out, and as a result,
The formation of an oil film by the lubricants O1 and O2 is maintained satisfactorily for a long time, and the bearing housing a
It is possible to reliably prevent the outside air containing moisture and salt from entering the inside.

As shown in FIG. 4, the closing member 18 may be sandwiched between the bottom of the recess b7 of the sealing member 16 and the bottom plate 12 of the blowing means 7. In this case, the gap where the outside air containing moisture and salt tends to enter the bracket 6 side is only a small gap between the closing body 18 and the rotor shaft 4a. As a result, the moisture and salt and the like are reduced. Intrusion of the contained outside air into the bracket 6 can be suppressed as much as possible.

Next, the second embodiment of the present invention will be described with reference to FIGS.
An example will be described. In the second embodiment, the same members as those in the first embodiment will be described by the same reference numerals. Figure 5
7, reference numeral 16a denotes a sealing member of the second embodiment, which is made of a material having excellent elasticity such as rubber or a synthetic resin (for example, polytetrafluoroethylene). As shown in FIGS.
A small-diameter small ring portion having a large-diameter large ring portion b1 for covering the outer peripheral surface of the bearing housing a of the bracket 6 and an insertion hole b3 for inserting the rotor shaft 4a protruding from the through hole a1 of the bearing housing a. b
2 and is formed in a cap shape.

A recess b6 and a small ring b2 corresponding to the back wall of the bearing housing a inside the large ring b1 of the sealing member 16a.
The insertion holes b3 are provided with grooves b4 and b5 for filling lubricants O1 and O2, respectively. Further, at the tip of the small ring portion b2, the insertion holes b3 are provided with a rotor. Axis 4
cylindrical closed body 1 with a closed bottom that does not hinder rotation of a
A recess b8 is formed for fitting the recess 8a.

Next, the sealing member 16a is
When mounting in a groove, semi-solid viscous lubricants (eg, grease) O1 and O2 are filled in the concave grooves b4 and b5, and a collar 17 made of a synthetic resin excellent in oil resistance, heat resistance, and wear resistance. Is loosely fitted to the rotor shaft 4a, the rotor shaft 4a is inserted through the insertion hole b3 of the small ring portion b2, and the large ring portion b1 is inserted into the bearing housing a of the bracket 6 as shown in FIG. The sealing member 16a is attached to the back of the bracket 6 by fitting using the elasticity of the large ring portion b1.

Thereafter, a cylindrical closed-bottomed body 18a made of synthetic resin having excellent oil resistance, heat resistance and wear resistance is attached to the rotor shaft 4a protruding from the insertion hole b3 of the small ring portion b2. The plug 18a is loosely fitted with the side face facing the insertion hole b3 (see FIG. 7), and the tip of the sealing member 16a is fitted with the closing member 18a fitted in the recess b8 of the tip of the sealing member 16a. 6 is brought into contact with the center of the bottom plate 12 of the blowing means 7, and in this state, the bottom plate 12 and the electric motor 1 are integrally connected and fixed using mounting bolts and nuts (not shown). Thus, the blower A is configured as shown in FIG.

As described above, in the second embodiment, the insertion hole b3 of the sealing member 16a is closed by the closing member 18a within a range that does not hinder the rotation of the rotor shaft 4a.
It is possible to prevent the outside air containing dust and the like from entering the bearing housing a of the bracket 6 from the mounting hole 12a of the bottom plate 12 through the insertion hole b3. Further, since a minute gap is provided between the closing member 18a and the rotor shaft 4a so as not to hinder the rotation of the rotor shaft 4a, moisture, salt, and the like can be removed from the minute gap. The outside air containing the sealing member 1
However, an oil film is formed in the sealing member 16a by the lubricants O1 and O2, and the oil film can prevent the invasion of the outside air containing moisture and salt. Therefore, the reliability of the electric motor 1 can be improved satisfactorily.

In addition, even when the blower A is used with the suction port 14 side facing downward (ie, the closing body 18a is on the lower side), the insertion hole b3 is closed by the bottom of the closing body 18a. The lubricant O softened from the through hole b3.
1, O2 can be prevented from leaking to the outside,
The formation of an oil film by the lubricants O1 and O2 can be maintained well, and the intrusion of outside air containing moisture, salt, and the like into the bearing housing a of the bracket 6 can be reliably prevented.

Next, a third embodiment of the present invention will be described with reference to FIGS. In the third embodiment, the same members as those in the first embodiment will be described by the same reference numerals.
8 to 10, reference numeral 16b denotes a sealing member of the third embodiment, which is made of a material having excellent elasticity such as rubber or a synthetic resin (for example, polytetrafluoroethylene). As shown in FIGS. 6, a small-diameter small ring b2 having a large-diameter large ring b1 covering the outer peripheral surface of the bearing housing a and an insertion hole b3 for inserting the rotor shaft 4a protruding from the through-hole a1 of the bearing housing a. And is formed in a cap shape.

A recess b6 and a small ring b2 corresponding to the back wall of the bearing housing a inside the large ring b1 of the sealing member 16b.
The insertion hole b3 is provided with grooves b4 and b5 for filling lubricants O1 and O2, respectively. Further, the insertion hole b3 is provided on the left side of the groove b5 (left side in FIG. 9). 3), a fitting groove b9 for fitting a ring-shaped closing body 18b for closing the insertion hole b3 within a range that does not hinder the rotation of the rotor shaft 4a is provided. The ring-shaped closing member 18b has a smaller diameter than the insertion hole b3, and
A through hole 18b1 slightly larger in diameter than the rotor shaft 4a is formed.

Next, the sealing member 16b is attached to the bracket 6
First, the ring-shaped closing member 18b is fitted into the fitting groove b9 provided around the insertion hole b3 of the sealing member 16b. When the closing member 18b is fitted in the fitting groove b9, for example, as shown in FIG. 11A, the sealing member 16b is attached to a convex jig X placed on a work table or the like. In this state, the pressing jig Y fitted with the closing member 18b is pressed and urged toward the convex jig X side. Since the sealing member 16b is formed of a material having excellent elasticity such as rubber or synthetic resin, the closing member 18b fitted to the pressing jig Y expands the insertion hole b3 of the sealing member 16b. While being opened, it is inserted to the position of the fitting groove b9, and is fitted into the fitting groove b9 as shown in FIGS. 9 and 11B. Thereafter, the pressing jig Y is withdrawn from the closing body 18b, so that the closing
The fitting of b into the fitting groove b9 is completed.

As described above, the closing member 18b is inserted into the fitting groove b9.
Then, each groove b4 of the sealing member 16b is
, B5 are filled with lubricants O1 and O2, and the thin plate-shaped collar 17 made of synthetic resin is loosely fitted to the rotor shaft 4a, and the rotor shaft 4a is inserted into the insertion hole b3 of the small ring portion b2 and the ring-shaped portion. Through the through hole 18b1 of the closing body 18b
To the back of the bracket 6. Thereafter, the sealing member 1
As shown in FIG. 9, the tip of the bottom plate 1 of the blowing means 7
8, the bottom plate 12 and the electric motor 1 are integrally connected and fixed to each other using mounting bolts and nuts (not shown) in this state, thereby forming the blower A as shown in FIG. 8. .

As described above, in the third embodiment, the through-hole 18b having a smaller diameter than the insertion hole b3 and a slightly larger diameter than the rotor shaft 4a is formed in the fitting groove b9 provided around the insertion hole b3.
1, the insertion hole b3 can be closed in a state where the rotor shaft 4a is inserted through the through hole 18b1. Dust and the like can be reliably prevented from entering the bearing housing a of the bracket 6. Further, from a minute gap between the through hole 18b1 of the closing member 18b and the rotor shaft 4a,
Although outside air containing moisture and salt tends to enter the bracket 6 side, an oil film is formed by the lubricants O1 and O2 inside the sealing member 16b (on the right side of the closing body 18b in FIG. 9). Therefore, the infiltration of the outside air can be satisfactorily prevented by the oil film, and as a result, the electric motor 1 can be used stably for a long period of time.

Further, even when the blower A is used with the suction port 14 side facing downward, the lubricants O1 and O2 forming the oil film in a softened state are filled with the insertion holes b3 of the sealing member 16b.
Can be prevented from leaking to the outside by the ring-shaped closing member 18b fitted in the fitting groove b9 provided around the insertion hole b3, so that the formation of the oil film by the lubricants O1 and O2 can be performed for a long time. It can be maintained well.

Next, a fourth embodiment of the present invention will be described with reference to FIGS. In the fourth embodiment, the same members as those in the first embodiment will be described by the same reference numerals. 12 to 14, reference numeral 16c denotes a sealing member of the fourth embodiment, which is made of, for example, a synthetic resin (for example, polytetrafluoroethylene) having high elasticity and abrasion resistance.
As shown by 3 and 14, a large-diameter large ring portion b1 for covering the outer peripheral surface of the bearing housing a of the bracket 6 and an insertion hole for inserting the rotor shaft 4a protruding from the through hole a1 of the bearing housing a. b3
And a small ring b2 having a small diameter.

A recess b6 and a small ring b2 corresponding to the back wall of the bearing housing a inside the large ring b1 of the sealing member 16c.
The insertion hole b3 is provided with grooves b4 and b5 for filling lubricants O1 and O2, respectively, and furthermore, on the side (left side in FIG. 13) of the insertion hole b3 corresponding to the bottom plate 12. At the opening, a thin film-like closing member 18c for closing the insertion hole b3 within a range that does not hinder the rotation of the rotor shaft 4a is provided with a through hole 18c1 having a diameter smaller than that of the rotor shaft 4a at the center thereof. Are formed integrally with the small ring portion b2. In addition,
The closing member 18c may be formed on the left side of the groove b5 in FIG. 13 (that is, closer to the opening than the groove b5).

Next, the sealing member 16c is attached to the bracket 6
In the case where the sealing groove is mounted on each of the grooves b4 and b5 of the sealing member 16c,
Are filled with lubricants O1 and O2, and a thin plate-shaped collar 17 made of a synthetic resin is loosely fitted to the rotor shaft 4a. The rotor shaft 4a is inserted into the insertion hole b3 of the small ring portion b2 and a thin film-shaped plug. Body 1
The large ring b1 is attached to the back of the bracket 6 by passing through the through hole 18c1 of 8c. Thereafter, as shown in FIG. 13, the distal end of the sealing member 16c is brought into contact with the center of the bottom plate 12 of the blowing means 7, and in this state, the bottom plate 12 and the electric motor 1 are attached to each other by using mounting bolts and nuts (not shown). Connected together
By fixing, a blower A is configured as shown in FIG.

As described above, in the fourth embodiment, by inserting the rotor shaft 4a into the through hole 18c1 of the thin film-like closing member 18c formed at the opening of the insertion hole b3, the closing member 18c is removed. As shown in FIG. 13, the insertion hole b3 is closed by sliding the rotor shaft 4a so as not to hinder its rotation. Is the bearing housing a of the bracket 6
Can be well prevented from entering the inside. In addition,
As described above, even if the closing member 18c is in sliding contact with the rotor shaft 4a, the closing member 18c is formed in a thin film of a synthetic resin having high wear resistance. It does not hinder.

Even if outside air containing moisture, salt, etc., enters the bracket 6 side, an oil film is formed inside the sealing member 16c by the softened lubricants O1, O2. The oil film makes it possible to satisfactorily prevent moisture or salt contained in the outside air from entering the bearing housing a of the bracket 6, and as a result, the electric motor 1 can be used stably for a long period of time. .

Further, when the blower A is used with the suction port 14 side facing downward, the outer peripheral surface of the rotor shaft 4a
The thin film-like closing member 18c formed at the opening of the insertion hole b3 is
Since the sliding contact is made without obstructing the rotation of the rotor shaft 4a, the lubricants O1 and O2 softened by the heat generated during the rotation of the rotor 4 are prevented from leaking out of the insertion hole b3 to the outside. It can be reliably prevented.

[0047]

As described above, according to the present invention, a sealing member made of a material having excellent elasticity, such as rubber or synthetic resin, is provided on the outside of the bracket from which the rotor shaft protrudes, and the rotor shaft is inserted through the insertion hole. Is inserted in a state where it is inserted, and at the tip end side of the sealing member where the rotor shaft projects, the insertion hole is closed in a range that does not hinder the rotation of the rotor shaft. , A ring shape, a thin film shape, or the like is provided, so that dust or the like contained in the outside air passes through the through hole of the sealing means and from the through hole of the bracket to the inside of the bearing housing due to the presence of the close body. As a result, it is possible to satisfactorily solve such a problem that the dust or the like intrudes into the bearing housing and thereby lowers the rotation function of the ball bearing. Drive in a stable state for a long time Door can be.

Also, the rotor shaft is arranged so that
Due to being inserted in a state where a minute gap is provided so as not to hinder the rotation, moisture or salt contained in the outside air from the minute gap tries to enter the sealing member,
A groove is formed in each of the portions corresponding to the insertion hole and the back of the bracket of the sealing member, and the semisolid viscous lubricant filled in the groove is softened by heat generated when the rotor rotates. Since an oil film of the lubricant is formed between the groove and the corresponding rotor shaft and the back surface of the bracket,
It is possible to satisfactorily prevent the moisture, salt, and the like from entering the bearing housing through the insertion hole. Therefore, it is possible to suppress the occurrence of the problem that the ball bearing is rusted due to the invasion of the moisture or the salt and the rotation function is reduced, and the driving of the electric motor becomes difficult, thereby improving the reliability of the electric motor. .

Further, when the motor equipped with the sealing member is used in a downward state (a state in which the closing member provided on the sealing member is on the lower side), the groove formed around the inside of the sealing member is used. Even in a state where the filled lubricant is softened by the heat generated when the rotor rotates, the insertion hole of the sealing member is closed by the closing body in a range that does not hinder the rotation of the rotor shaft. It is possible to reliably prevent the lubricant in the softened state from leaking to the outside, and as a result, it is possible to favorably maintain the formation of an oil film by the lubricant.

In addition, the sealing member itself can be easily manufactured by injection molding or molding, and assembling can be performed easily, so that the bearing device for the electric motor can be easily and inexpensively manufactured. Can be manufactured.

[Brief description of the drawings]

FIG. 1 is a cutaway side view of a main part of a blower showing a use state of an electric motor including a bearing device according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing the bearing device according to the first embodiment of the present invention.

FIG. 3 is a perspective view showing a sealing member used in the bearing device of the first embodiment in a longitudinal section.

FIG. 4 is a longitudinal sectional view showing another example of the first embodiment of the present invention.

FIG. 5 is a cutaway side view of a main part of a blower showing a use state of an electric motor including a bearing device according to a second embodiment of the present invention.

FIG. 6 is a longitudinal sectional view showing a bearing device according to a second embodiment of the present invention.

FIG. 7 is a perspective view showing a sealing member used in the bearing device of the second embodiment in a longitudinal section.

FIG. 8 is a cutaway side view of a main part of a blower showing a use state of an electric motor including a bearing device according to a third embodiment of the present invention.

FIG. 9 is a longitudinal sectional view showing a bearing device according to a third embodiment of the present invention.

FIG. 10 is a perspective view showing a sealing member used in the bearing device of the third embodiment in a longitudinal section.

FIG. 11 is an explanatory diagram for explaining an operation of attaching a ring-shaped closing body to a sealing member used in the bearing device of the third embodiment.

FIG. 12 is a cutaway side view of a main part of a blower showing a use state of an electric motor including a bearing device according to a fourth embodiment of the present invention.

FIG. 13 is a longitudinal sectional view showing a bearing device according to a fourth embodiment of the present invention.

FIG. 14 is a perspective view showing a sealing member used in a bearing device of a fourth embodiment in a longitudinal section.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electric motor 4 Rotor 4a Rotor shaft 5, 5a Ball bearing 6, 6a Bracket 16, 16a, 16b, 16c Sealing member 17 Collar 18, 18a, 18b, 18c Closure a Bearing housing b4, b5 First, second Groove of O1, O2 lubricant

Claims (7)

[Claims] 1. A pair of brackets having a rotor attached to a rotor shaft, a stator core opposed to the rotor and sandwiched from both sides, and a bearing housing formed at a center position.
Ball bearings mounted on both ends of a rotor shaft, wherein the rotor is rotatably inserted into a stator core, and ball bearings at both ends of the rotor shaft are fitted into bearing housings from both sides thereof. In a motor configured by attaching a pair of brackets rotatably supporting a rotor to a stator core with a rotor shaft protruding from a through hole of one of the brackets, a bracket having the rotor shaft protruding is provided. On the outside, a sealing member made of a material with excellent elasticity such as rubber,
The rotor shaft is inserted in a state where the rotor shaft is inserted through the insertion hole, and the insertion hole is closed on the tip side of the sealing member where the rotor shaft projects so long as the rotation of the rotor shaft is not hindered. A bearing device for an electric motor, wherein a closing body is provided. 2. A recess for accommodating a thin plate-like closing member is provided at a tip of the sealing member, and the thin plate-like closing member projects from the tip of the sealing member in the recess. The bearing device for an electric motor according to claim 1, wherein the insertion hole can be closed from the outside by being housed in a state of being loosely fitted to the rotor shaft. 3. A recessed portion for fitting a closed-end cylindrical closing body is formed at a distal end of the sealing member, and the opening side of the closed-end cylindrical closing body is inserted into a through-hole. Loosely fitted to the rotor shaft protruding from the tip of the sealing member in a state where
2. The bearing device for an electric motor according to claim 1, wherein the insertion hole can be closed from the outside by being fitted into the concave portion. 3. 4. A through hole is formed in the insertion hole of the sealing member at the tip end side, and the diameter of the insertion groove is smaller than the insertion hole and slightly larger than the rotor shaft. 2. The bearing for an electric motor according to claim 1, wherein the insertion hole can be closed in a state where a rotor shaft is inserted into the through hole by fitting a ring-shaped closing body having a through hole. apparatus. 5. A thin film closing member having a through hole smaller in diameter than a rotor shaft is formed integrally with a sealing member at an opening of an insertion hole opening at a tip end of the sealing member. The rotor shaft is inserted into the through hole, and the closing hole is made to slide on the outer peripheral surface of the rotor shaft in a deformed state using elasticity, so that the insertion hole can be closed. Item 2. An electric motor bearing device according to item 1. 6. The sealing member has grooves formed in an insertion hole through which a rotor shaft is inserted and an inner surface corresponding to an outer surface of the bearing housing, and a semi-solid viscous groove is formed in these grooves. 6. The bearing device for an electric motor according to claim 2, wherein a lubricant is filled to form an oil film of the lubricant between the rotor shaft and the groove. 7. A thin plate-like collar having a small coefficient of friction is loosely fitted to a rotor shaft between the sealing member and the bearing housing, and is filled in a concave groove at a position corresponding to the collar of the sealing member. 7. The bearing device for an electric motor according to claim 6, wherein an oil film of the lubricant is formed between the sealing member and the collar using the semi-solid viscous lubricant.